How to Debug "Stop 0xC2" or "Stop 0x000000C2" Error Messages

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Article ID: 265879 - View products that this article applies to.
This article was previously published under Q265879
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This article applies to Windows 2000. Support for Windows 2000 ends on July 13, 2010. The Windows 2000 End-of-Support Solution Center is a starting point for planning your migration strategy from Windows 2000. For more information see the Microsoft Support Lifecycle Policy.
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SUMMARY

This article describes how to debug Stop C2 error messages.

MORE INFORMATION

Windows 2000 contains many built-in features that enhance the pool allocation process. A number of new stop codes have been added that help you locate drivers that do not function correctly. Because of these additional features, you may be able to find the root cause of the driver's malfunction by simple debugging.

The following procedure describes how to debug a OxC2 stop.

First, check the stop documentation. For example:
BAD_POOL_CALLER                              (0xC2)

The current thread is making a bad pool request.  Typically this is at a bad IRQL level or double freeing the same allocation, etc.

1 - type of pool violation the caller is guilty of.
6 - the pool address being freed is already free.
7 - the pool address being freed is already free.
8 - parameter 2 is the IRQL allocating at, parameter 3 is the pool type
9 - parameter 2 is the IRQL freeing at, parameter 3 is the pool type

Parameter 1 = 0x1, 0x2, or 0x4 :  Pool header has been corrupted
   Parameter 2 = Pointer to pool header
   Parameter 3 = First part of pool header contents
   Parameter 4 = 0

Parameter 1 = 0x6 :    Attempt to free pool which was already freed
   Parameter 2 = Reserved (__LINE__)
   Parameter 3 = Pointer to pool header
   Parameter 4 = Pool header contents

Parameter 1 = 0x7 :    Attempt to free pool which was already freed
   Parameter 2 = Reserved (__LINE__)
   Parameter 3 = Pointer to pool header
   Parameter 4 = 0

Parameter 1 = 0x8 :    Attempt to allocate pool at invalid IRQL
   Parameter 2 = Current IRQL
   Parameter 3 = Pool type
   Parameter 4 = Size of allocation

Parameter 1 = 0x9 :    Attempt to free pool at invalid IRQL
   Parameter 2 = Current IRQL
   Parameter 3 = Pool type
   Parameter 4 = Address of pool

Parameter 1 = 0x40 :    Attempt to free usermode address to kernel pool
   Parameter 2 = Starting address
   Parameter 3 = Start of system address space
   Parameter 4 = 0

Parameter 1 = 0x41 :    Attempt to free a non-allocated nonpaged pool 
address
   Parameter 2 = Starting address
   Parameter 3 = physical page frame
   Parameter 4 = highest physical page frame

Parameter 1 = 0x50 :    Attempt to free a non-allocated paged pool address
   Parameter 2 = Starting address
   Parameter 3 = Start offset in pages from beginning of paged pool
   Parameter 4 = Size in bytes of paged pool

Parameter 1 = 0x99 :    Attempt to free pool with invalid address (or 
corruption in pool header)
   Parameter 2 = Address being freed
   Parameter 3 = 0
   Parameter 4 = 0

				
After you have collected detailed information about the 0xC2 stop, use the debugger:
E:\bin>i386kd -z  K:\DOWNLOAD\memory.dmp
Loading Dump File [K:\DOWNLOAD\memory.dmp]
Full Kernel Dump File
...
0: kd> !reload                GOOD HOUSEKEEPING DONE HERE

0: kd> dd kibugcheckdata  l8    DUMPING THE ERROR

8047fba0  000000c2 00000007 00000b68 815bade0
8047fbb0  815bade8 e1007000 00000000 818988c0

0: kd> kv                     DUMPING STACK         

ChildEBP RetAddr  Args to Child
bdce0348 be11dc84 e1fff000 a08d0008 000007f8 banshee!vH3ImageTransferMm32
bdce037c be116f18 be85fd78 00000001 bdce03dc banshee!vMmXferNative
bdce03ac be113eec e1fff000 e25e2a38 bdce03dc banshee!vPutBits
bdce03e8 a008e47f e1ff86f8 e25e2a38 e1fef908 banshee!DrvCopyBits
bdce0430 a008e899 be113d40 bdce04d8 e1ff86f8 win32k!OffCopyBits
bdce04e4 a008e4d1 e1ff86f8 e25e2a38 00000000 win32k!SpBitBlt
The stop documentation indicates that memory is being freed. This information is indicated by the following line:
Parameter 1 = 0x7: Attempt to free pool which was already freed.
But the stack shows that the video card is in the process of a write, so you must continue to investigate. First, you must determine if this computer is a multiprocessor.
0: kd> ~1                     SWITCH PROC

1: kd> kv                     DUMPING STACK  

ChildEBP RetAddr  Args to Child
bde81b7c 8046894d 815bade8 00000000 be03bb2b ntkrnlmp!ExFreePoolWithTag
bde81b88 be03bb2b 815bade8 be03ca94 815bade8 ntkrnlmp!ExFreePool
00000128 00000000 00000000 00000000 00000000 BADDRIVER
				
The preceding text indicates that memory is freed through the driver drivername. This could be the possible root cause.

Next, define the driver:

1: kd> !drivers               
Loaded System Driver Summary

Base       Code Size       Data Size       Driver Name       Creation Time
80400000 139f40 (1255 kb) 4f3c0 (316 kb) ntoskrnl.exe  Tue Dec 07 14:05:26 1999
80062000   ffe0 (  63 kb)  3d60 ( 15 kb)      hal.dll  Tue Nov 02 20:14:22 1999
ed410000   1760 (   5 kb)  1000 (  4 kb)  BOOTVID.dll  Wed Nov 03 20:24:33 1999
ed49c000   1b00 (   6 kb)   680 (  1 kb) gameenum.sys  Sat Sep 25 14:35:57 1999
ed080000   a000 (  40 kb)  20c0 (  8 kb) VIDEOPRT.SYS  Sat Nov 06 16:55:20 1999
bfdcf000  1d480 ( 117 kb)  7520 ( 29 kb)   mga64m.sys  Mon Nov 29 20:47:46 1999
bfdbc000  11600 (  69 kb)  1600 (  5 kb) el90xnd5.sys  Fri Oct 29 17:54:34 1999
ed090000   3a60 (  14 kb)  5980 ( 22 kb)  banshee.sys  Fri Oct 29 19:00:56 1999
ed5df000    2e0 (   0 kb)   4a0 (  1 kb)  audstub.sys  Sat Sep 25 14:35:33 1999
ed370000   33e0 (  12 kb)   a40 (  2 kb)   raspti.sys  Fri Oct 08 16:45:10 1999
ed0c0000   c5e0 (  49 kb)  20e0 (  8 kb) parallel.sys  Fri Oct 22 18:00:54 1999
ed5e0000    580 (   1 kb)   540 (  1 kb)   swenum.sys  Sat Sep 25 14:36:31 1999
be552000  72a60 ( 458 kb) 13c40 ( 79 kb)   mga64d.dll  Tue Nov 30 04:33:19 1999
be113000  36f00 ( 219 kb)  7a20 ( 30 kb)  banshee.dll  Tue Nov 30 04:31:18 1999
be031000   FFFF (  FF kb)  FFFF (  F kb) BADDRIVER.sys Mon Feb 30 23:22:43 2000

TOTAL:   7f8dc0 (8163 kb) 172140 (1480 kb) (    0 kb     0 kb)
				
The preceding text indicates that the driver is used by a third-party software package. This driver is most likely the cause of the error. To further investigate this issue, search the Microsoft Knowledge Base for more information. Also, check the file properties with Windows Explorer or by using a Hex editor on the file itself. You can also check the vendor's Web site for any updates or known issues.

Properties

Article ID: 265879 - Last Review: October 23, 2007 - Revision: 5.5
APPLIES TO
  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional Edition
  • Microsoft Windows 2000 Datacenter Server
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